WordNet (r) 3.0 (2006):

busboy
    n 1: a restaurant attendant who sets tables and assists waiters
         and clears away dirty dishes [syn: busboy, waiter's
         assistant]

Moby Thesaurus II by Grady Ward, 1.0:

49 Moby Thesaurus words for "busboy":
   Aquarius, Ganymede, Hebe, barkeep, barkeeper, barmaid, barman,
   bartender, bearer, bheesty, caddie, cargo handler, carhop, carrier,
   carrier pigeon, carter, common carrier, conveyer, coolie,
   counterman, cupbearer, drayman, express, expressman, freighter,
   gun bearer, hauler, headwaiter, homing pigeon, hostess,
   letter carrier, litter-bearer, porter, redcap, shield-bearer,
   skycap, sommelier, stevedore, stretcher-bearer, the Water Bearer,
   transporter, truck driver, trucker, wagoner, waiter, waitress,
   water boy, water carrier, wine steward